Air-eliminator.



w.1. BUBKART. AIR ELIMJNATOR.

APPLICATION HLED NOV. 20,1916

1,2 7,218. Patented No v. 20, 1917.

INVENTOR Willin.m I Bvrlmri' WI'IYNEBSES I invention will be more fullyset forth in the UNITED STATES PATENT OFFICE.

.WIILLIAM J. BURKART, OE PITTSBURGH, PENNSYLVANIA, ASSIGNOR TOPITTSBURGH ENGINEERING COMPANY, A CORPORATION OF PENNSYLVANIA.

AIR-ELIMINATOR.

Specification of Iletters Patent. Patentqd Nov. 20, 1917.

Application filed November 20, 1916. Serial No. 132,447.

To all whom it may concern:

Be it known that I, WVILLIAM J. Bummer, a resident of Pittsburgh, in thecounty of Allegheny and State of Pennsylvania, have invented a new anduseful Improvement in" escape, of air from a steam circulation system ata point in the return line; the prevention of the escape of water andsteam; and mechanism for controlling the air passage for these purposesof simple construction and positive operation; Another ob eet of theinvention is to provide means to prevent the drawingsof air' into thepipes through the escape-port; and thisis sealed device.

The various uses and advantages of the following specification,illustrated by the ae-' companying drawings, wherein an elevation of theapparatus is shown, the movable parts and their casings being shown insection.

Air eliminators are in use having in view the same general objects ashere, but the construction has been different, and have had defects inoperation which have been eliminated in the present case.

In asystemof heating by steam, a boiler is connected to a line whichleads through the various rooms and radiating units to be heated andthen returns to the boiler. In various ways air gets into thecirculation, and it isimportant that this be eliminated. A part of thiesteam is condensed in the line and radiators, and the water so formed isforced back into theboiler and so used again. The steam that returns isalso valuable and must not be allowed to escape through the aireliminator. Therefore the problem is to permit ready expulsion of airthrough a device locked against passage of steam or water. There is afurther problem in that air must not be allowed to pass into the systemby reverse flow through the air eliminator; and this must be positivelyguarded against, since a sudden chilling of the radiators causes a largeamount of steam to condense and so creates a partial vacuum in the line,which would draw air through done by a Heat the escape port if nomeansof prevention were provided.

All of these functions are-found in the present invention, whichcomprises a return line 1 having a T-connection to a pipe 2 leadingdownwardto thello tver port of a boiler in the circulating system and apipe 3 leading upward to the air ,eliminating apparatus. This consistsof a casing 4 having an opening 5 to the pipe 3, and an opening 6 at itstop to a second casing 7. In the easing 4 a large float 8 is.mounted ona lower stem 9 a nd upper stem 10; the lower stem passing through anopening in the lower wall of the casing and so acting as a guide for thevertical movement of the float. A collar is fixed on stem 9 and seats onthe lower wall of the casing 4 to limit the downward travel of thefloat, as will be obvious. The upper stem 10 is similarly guided by anopening in the upper part of the casing, here shown as a rentrantsupplementary a valve disk 16 is fixed, adapted when the float is raisedto cooperate with seat- 15 to close the passage 17 between casings 4 and7.

.Another; beveled valve seat 18 is provided in the casing 7 at the upperend of passage 17. The chamber 19, formed by easing 7, is closed by athreaded member 20, having free ports 21 therethrough, and carrying athermostat member 22, inside chamber 19. This thermostat consists of astem, in two parts, one being fixed to the casing wall, the othercarrying a valve disk 23 adapted to cooperate with seat 18 toel'bse'tlgrk5 17, when a volatile liquid con-31 drums 24 expands tolengthen the stem of the thermostat member. This thermostat is notitself ne'w; its operation is well known;

-wall 12, forming a small chamber 13, con- I 'nected to the main chamber14 by ports 6,

and noextended description is here neeestop of casing 26, and in thechamber 28, formed by said casing, carries'a bell-shaped open terminal29, ending below the pipe 27. The casing 26 is closed by a threaded memher 30, to make the chamber 28 fluid tight at the bottom, and it isfilled with water to the height of pipe 27. A float 31, in the form of ahollow sphere, of any suitable material, is held in the mouth ofbell-shaped terminal 29 by its bouyancy in the water.

The operation is as follows: Steam generated in a boiler (not shown)passes through the heating and radiating system (not shown) and thenreturns by pipes 1 and 2 to the boiler. A certain amount of Water ofcondensation and of air aremixed with steam in the return line. Thewater, of course, flows down pipe 2, and collects in that pipe, whichconnects by a non-return valve to the feed supply of the boiler. Whenpressure in the system mounts high enough to equalize (or nearlyequalize) the pressure above this water and the boiler pressure, itpasses into the feed supply and is used again to make steam.

Air in the return pipe will rise in pipe 3,

pass freely through chamber 14, passage 17,

chamber 19, pipe 25; depress the ball-float 31 and out the pipe 27 tothe atmosphere.

Should a large amount of water come through pipe 1 so as to back up intochamher 14, the float 8 will rise, seating valve disk 16 and closingpassage 17 against esca e of Water. Pressure will eventually build upand the waterbe forced out to the boiler. I, I

Should. steam come through the return pipe to the eliminator, it willrise through chamber 14 andinto chamber 19, enveloping the theremostattherein. The steam is of course at a temperature above 212 degreesFahrenheit, and the thermostat is so made that such temperature willexpand it sulfieiently to seat the valve disk 23, and so close I thepassage 17 against escape of steam."

Sometimes a sudden chilling of the radiators condenses a large amount ofsteam and creates a partial vacuum in the system.

In such case air cannot reenter by the eliminator, even though bothvalves'16 and 23 be unseated, because the ball float 31 is always inposition to close the mouth-piece v 29 against any upward fiow' therein,and the greater the pressure, the tighter this closure.

It will be observed by those familiar with Eli not be displaced orstick, and that the whole 60 apparatus is simple and positive inoperation. The thermostat is ordinarily mounted so as to be adjustablewith relation to the valve seat, though this is not here shown.

f In a steam heating system comprising a return line, an air eliminatorcomprising a easing connected to the return line, a float in the casinghavinga guiding stem and a valve thereon adapted to close a passage fromthe casing, a thermostatically controlled valve also controlling thepassage from the casing, and a pipe extending downward from the-passagethrough the casing having a bell-shaped terminal, a.casing surroundingthe terminal, a ball float in said casing adapted to seat against theterminal and form a non-return valve, and a lateral V passage 'from thecasing above the level of the terminal. Y In testimony whereof, I havehereunto set my hand. v

WILLIAM J. BURKART. Witnesses:

' GLENN H. Lnmesonn, 1J0. BAILY BROWN.

